Refrigerated display cabinet



June 2 1942.

L. F. CLERC REFBIGERATED DISPLAY CABINET Filed May 1, 1939 8 Sheets-Sheet 2 0000 0 000000000000 oooo June 2, 1942. L. F. CLERC 2,285,110

REFRIGERATED I DISPLAY CABINET Filed May 1, 1939 8 Sheets-Sheet 3 June 2, 1942. L. F. CLERC REFRIGERATED DISPLAY CABINET Filed May 1, 1939 a sneak -sheet 5 June 2, 1942. L. F. cLERc I REFRIGERATED DISPLAY CABINET Filed May 1, 1939 8 Sheets-$heet 7 June 2; 9 2- 1.. F. CLERC 2,285,110

REFRIGERATED DISPLAY CABINET Filed Ma 1, 1939 a Sheets-Sheet 8 1,2 165 57 15E I66 1&2 56 156195 sra rss ear 1- Claim.

My invention relates generally to refrigerated display cabinets, and more particularly to improvements in cabinets of this type whereby the food products which are contained in the cabinet are readily accessible, so that the cabinet may be used for a self-service in grocery stores and the like.

It is an object of my invention to'provide an approved refrigerated display cabinet in which is incorporated a conveyor carrying the food past doors which may be opened by the customer desiring to purchase food products carried by the conveyor.

A further object is to provide a food display cabinet in which a large variety of food products may be stored and displayed, and in which the food products move past doorways through which they may be removed from the cabinet, and in which the kind of food product adjacent the doorway is indicated to the customer.

A further object is to provide a refrigerated display cabinet in which access to the cabinet is obtained through relatively small doors located near the top of the cabinet, whereby the transfer of heat to the interior of the cabinet upon opening the doors is at a low rate.

A further object is to provide an improved refrigerated food display cabinet in which is provided a food storage chamber which may be elevated to obtain access to the food stored therein.

A further object is to provide a refrigerated display cabinet incorporating power operated means for conveying the contents of said cabinet past doorways formed therein, and arresting the operation of the conveying means whenever any one of the doors is opened.

A further object is to provide an improved refrigerated display cabinet in which the contents may be maintained at a uniformly low temperature.

A further object is to provide an improved refrigerated display cabinet in which a large quantity of packaged food products may be stored and displayed, and in which access may be had directly to any particular package.

A further object is to provide an improved food product conveying means for use in display cabinets.

A further object is to provide an improved control means for a conveyor driving mechanism whereby said conveyor may readily be stopped in any desired position with respect to the doors.

A further object is to provide an improved refrigerated display cabinet which is of relatively simple construction, may be economically (ill.

operated, and which will be efiective to maintain food products at any desired low temperature.

Gther objects will appear from the following description, reference being had to the accompanying drawings in which:

Figure 1 is a front elevation of the cabinet;

Figure 2 is a plan view thereof;

Figure 3 is a l'ragmentaryside elevation of one end of the cabinet, showing the food storage compartment in elevated position;

Figure 4 is a central vertical longitudinal sectiolnalview oi the cabinet, taken substantially on the line l-d in Figure 2;

Figure 5 is a vertical transverse sectional view, taken substantially on the line 55-501 Figure l;

Figure 6 is a view similar to Figure 5, taken on the line t% of Figure 1;

Figure 7 is a vertical transverse sectional view, taken on the line L-fl of Figure 4;

figure 8 is a fragmentary sectional view, taken on the line t8 of Figure 2, and showing particularly the conveyor driving mechanism;

Figure Q is a horizontal sectional view taken on the line @9 of Figure and showing particularly the mechanism for elevating the storage compartment, and for controlling the operation of the conveyor;

Figure ii) is a central vertical sectional View in a plane extending longitudinally of the cabinet, and taken on the line ld--ill of figure 9;

General description It is believed that a clear understanding of the detailed description of the cabinet will be more readily obtained if it is prefaced with this brief general description of the invention.

The cabinet consists of thoroughly heat-insulated walls, and may be considered as divided into three general sections. One section contains the refrigerating unit, a blower, and a conveyor driving mechanism, togetherwith the motors and controls therefor. The second section constitutes the food cabinet proper, and has incorporated therein a conveyor carrying a plurality of trays or baskets, in which the food to be sold is placed. This conveyor moves the trays relatively slowly through a closed circuit, past manually openable doors located in the top of the cabinet along both sides thereof.- These doors may be opened by the customer, and the operation of the conveyor arrested so that the customer may conveniently withdraw products from the trays or baskets carried by the conveyor, the conveyor being arrested during the time that any one of the doors is opened. An indicator which may carry legends giving the prices and descriptive of the products contained in the various trays or baskets is operated in synchronism with the conveyor, so as to indicate the particular product which is in the trays adjacent the doors. The third section of the cabinet comprises a storage compartment containing a plurality of shelves which may be elevated above the plane of the top of the cabinet to enable the groceryman readily to remove and replace food products therein. Manually controlled power operated means are provided for elevating and lowering this storage cabinet.

The main food containing section of the cabinet is cooled by means of -a blast of cold air circulated in series through the food containing chamber and pasta heat transfer apparatus, in which surplus moisture is removed from the air, and the air lowered to a temperature sufiicient to preserve the particular food products in the cabinet. The heat transfer device may be cooled by any suitable type of refrigerating unit, and is so constructed that in the event of failure of the refrigerating system, dry ice maybe utilized as a refrigerating medium.

The cabinet is equipp d with static switch operated controls, whereby the air circulating blower is operated only when necessuitable th'ermosary to maintain a predetermined low temperature, and the refrigerating unit is similarly supplied with the usual controls for regulating its operation. L

Detailed description of cabinet The cabinet consists of a well insulated container, preferably of the shape'shown in Figs. 1 and 2, and comprising. an outer wall I8 of sheet metal supported upon a structural iron frame. The cabinet is preferably raised above the floor by a short pedestal I2 so as to provide a space for the toes of persons removing products from v the top of the remainder of the cabinet to obtain access thereto. The cabinet is provided with standards 28 supporting a panel 22 for the reception of advertising indicia, and for supporting a housing 24 having windows 28 through which the indicia on an indicating drum may be observed.

Referring to the middle section B, as best shown in Figs. 4, 5 and 6, this section is separated from the remaining sections by end partition walls 28 and 88, the end wall 38 being suitably perforated (Fig. 6) so as to afford communication between the center section B and section C.

Within the section B are a plurality of foodcarrying trays or baskets 32, which are preferably made of perforated sheet metal or other reticulated or foraminated metal so as to permit relatively free circulation of air through the walls thereof. The ends of the trays have bearing studs 84 secured thereto adjacent the top thereof, these studs projecting into bearing apertures formed in brackets 88 which are secured to a chain 88 in suitable spaced relation with respect to one another. The chains 88 mesh with sprockets 48, 42. In the construction illustrated, there are twelve trays arranged in two groups of six each, each group being supported and moved by a pair of chains 38. The trays are adapted to be moved past the doors l8 which, p n bein raised, permit the customer to remove articles of food from the trays. By suitable control means hereafter to be described, the customer may control the movement of the trays and stop the trays when a tray containing the particular food desired is adjacent the door I8, the contents of the trays being determined by observation of the signs on indicators 44 which are rotated .in synchronism with the trays 82, and the indicia of which are observable through the win- .dows 28. The contents of the trays may be observed through a window 48 which comprises a plurality of panes of glass hermetically sealed with respect to one anothenso as to prevent frosting due to the admission of moist air between the panes. The chamber is illuminated by a lamp 48, provided with a suitable generally tubular reflector 88.

Most of the apparatus for moving the trays is contained in a closed compartment 82, and is best shown in Figs. 7, 8 and 9.. This driving means consists of an electric motor 84 which, through a worm 88, drives a worm gear 88. The worm gear 58 is' fixed to a shaft 88, which carries a sprocket 82, which latter, through a chain 84, drives a sprocket 88. The sprocket 88 is secured to a shaft 88 which extends through the wall 28' being supported by a bearing I8 and at its inner end, in the compartment B, carries a-gear 'l2which meshes with a gear", the latter being rotatably mounted'on a shaft I8. The

' gear 14 meshes with a similar gear I8 freely rotatable on a shaft 88. The gears 14 and I8 have law clutches formed in their. hubs, which cooperate with slidable jaw clutch members 82 and 84, respectively, the latter being mounted to rotate with the shafts I8 and 88, respectively, be-

ing rotatably connected therewith by means of feather keys or the like. The ends of the shafts I8 and 88 carry sprockets 88 and 88, respectively. these sprockets driving larger sprockets 88 and 82 through chains'84 and 88 respectively. The sprockets 88 and 82 are mounted on stub shafts 84 and 88 respectively, which at their inner ends carry the previously mentioned sprockets 48 and 42, thereby moving the trays 82. The opposite (right hand Fig. 9) ends of the shafts I8 and 88 carry sprockets 81 and 88 respectively. which through chains and sprockets, similar to the chains 84, 88 and sprockets 88, 82.dri ve the lower sprockets 42 at the right hand (Fig. 10) end of the sectionB. The chains 38 at the opposite ends of one group of trays are thus driven in synchronism from a common shaft I8 or 88.

The two groups of trays are, however, separately controlled by means of handles 88, 88 which are suitably mounted adjacent the doors I8. Each of the handles 88, 88 is secured to the end of a rod I88 which at its lower end has an arm I82 rigidly secured thereto. A pull rod I84 is connected to each of the levers I82 by a suitable lost motion pin and slot connection, and is normally pulled to the left (Fig. 9) by a tension spring I88, the left hand end of each of the rods I84 being pivotally connected to the end of a lever I88 suitably pivoted upon a pin '8. The levers I88 carry yokes II2 which are rotatable with respect to the jaw clutch members 82 and 84. By clockwise rotation of the handle 88 the jaw clutch member 82 may be brought into en gagement with the complemental jaw clutch member formed on the hub of gear 14, and the shaft 16 is thus connected to the source. of power, for moving the group of trays which are adiacent the handle 98. In a similar manner, the handle 99 controls the movement of the group of trays adjacent it. Each of the handles, in addition to operating its associated jaw clutch member, is effective when operated as described to close a switch II4 which, as will hereinafter appear, controls the supply of current to the motor 54.

' In order to .prevent the movement of a group of trays under the force of gravity, assuming that the trays are unequally loaded, each of the levers I08 is adapted to move a locking rod H8 into engagement with notches formed in looking discs I18 which are rigidly secured to the shafts Hi and 80. Thus, when either of the jaw clutch *members 82 or 84 is disengaged, the associated group of trays is held against movement. It will be noted that the ends of the rods II 6 are guided and supported by a bracket I20 which is secured to the end wall 30.

The indicators 44 are mounted upon shafts I22 which are driven by chains I24 meshing with sprockets I26 secured to the ends of the shafts I22. The chains I24 also mesh with sprockets I28 carried on shafts I30, which also have secured thereto gears I32 which mesh with pinions I34 secured to the stub shafts 69.

Storage compartment elevator ported in a cabinet I38. The cabinet. I38 has the cover I8 rigidly secured thereto and is adapted for elevation, structurally built up guide-ways I40 forming channels for the reception of the legs I42 of T-shaped ubars secured to the sidewalls of the cabinet. =The cabinet is also guided for vertical movement by a channel I4I which receives and forms a track for a roller I48 which is attached to the cabinet I38.

The cabinet is counterbalanced by a weight I44 which is carried-"at the end of a cable I48, the cable extending about a pulley I48 and being attached to the lower end of the cabinet I38 by means of a bracket I49. Additional counterweights may be provided. The cabinet I38 is elevated and lowered'by power operated means controlled by handle I50which is secured to a rod I52, the lower end of the rod having an arm I58 rigidly secured thereto. The arm I58 has a rod -I56"pivotally secured at its extremity, this rool being-suitably guided through section B of the c-abi t and having-its left hand (Fig. 9) end pivotall'y secured to a'lever I60 which carries a yoke I62 for shift-ing a double jaw clutch member I88 longitudinally orra shaft I66. The jaw clutch lirein'ber Itidis-slidably keyed to the shaft I88 and is adapted taltern'a'tivelyto engage jaw clutch members I68 and i'lfi. The jaw clutch member I68 may be part of'the hub of a sprocket I'll which is' driven by a chain I12, the chain iii? beingin turn driven from the shaft 88 through a sprocket lid. The clutch member I18 may be formed integrally with the hub of asprocket I18 wli li 's j' driven through a chain I18 from a 'sprocketii'tii carried by the shaft I8. Q -TiiefcIutch members 488 and lit thus rotate -'i'n='opposite directions,'and upon engagement of the double jaw clutch member I88 with the clutch member I68 the shaft I86 is rotated in one direction, while when the clutch member I 64 is engaged with the clutch member I10, the shaft I88 is rotated in the opposite direction.

The right hand end (Fig. 9) of shaft I66 is supported in a suitable bearing bracket I82 and carries a bevel pinion I84 at its extremity. The bevel pinion I84 meshes with a bevel gear I88 carried on a shaft I88, likewise supported in the being secured at its extremity to a bracket 208 attached to the bottom of the cabinet I38. The other end of thecable 200 is attached to an anchor bracket 2I0 secured to the bottom of the cabinet I38. From the foregoing description of the drum and cable, it will be apparent that. rotation of the winding drum I98 in one direction will cause elevation of the cabinet I38 to the position in which it is shown in Fig. 3, while rotation of the winding drum I98 in the opposite direction' will cause the cabinet I38 to be lowered to the position in which it is shown in Fig. 10. It is necessary thus positively to elevate and lower the cabinet because of the fact that in some instances its weight plus that of its contents may not be fully counterbalanced by the weight or weights I44; while in other instances application of a force to lower it.

Means are provided to-hold the cabinet I38 in any position to which it may be elevated.

This means comprises a braking device 2 I 2 which is operable upon a brake drum 2I4 formed integrally with the winding drum I98, the brake device being normally held in braking position by a tension coil spring 2i 6. Whenever the handle I50 is operated either to raise or lower the cabinet I38, it is effective through the attachment of its lever i54 with a cable 2E8 to release the brake device 2I2. Operation of the handle I50 to cause elevation or lowering of the cabinet also closes a switch 220, which is connected in parallel with the switches H4, and when closed, energizes the motor 84.

Refrigerating system The apparatus for cooling the air in sections B and C of the cabinet is preferably a motor driven mechanical refrigerating unit which may be ofany well known construction. Means are preferably provided whereby dry ice may be used as the refrigerating medium, so that in the event of failure of the mechanical refrigerating unit,

located in section A of the cabinet, having its evaporator coils 228'enclosed in double walled open end tanks 238, which in turn are suitably supported within a housing 232, the tanks 238 being preferably filled with a liquid having a low freezing point, such as alcohol, and thus facilitating the transfer of heat from the inner walls of the tanks 238 to the air which flows through circuitous passageways formed within the tank by removable horizontal separator plates 234 and vertical separator plates 238. The tanks 238 and the separator plates which form the walls of the long circuitouspassageways through the tanks may be of the. construction shown in my copending application, Serial No. 256,028, filed February 13, 1939.

Air drawn from the food tion B of the cabinet is forced successively through the circuitous passageways of the two tanks by a blower 238 which is driven by a motor 248. The blower draws air upwardly through a conduit 242 (Fig 8), which is branched and connected to apertured conduits 244, the latter extending longitudinally of the section B adjacent to and at the sides of the bottom thereof. The air thus drawn from the food compartment of the cabinet through the conduits 244 and 242 is ejected under pressure through a conduit 246 into the circuitous passageway in the uppermost of the two tanks 238, from which the air flows through a conduit 248 to the circuitous passageway in the lower of the two tanks 238. After circulating through the circuitous passageways, the air is forced upwardly through the conduit 258, the latter conduit terminating in a horizontal apertured conduit 252 which extends along the top of the food compartment in section B at the center thereof. The end of the conduit 252 extends through the end partition wall 38, as shown in Fig. 10, so that some of the cooled air is forced into. section C of the cabinet to maintain the contents of. the storage cabinet I38 at a low temperature. A thermostat 254 (Fig. 10) is suitably located within the food compartment of section B, and is operative to control the supply of current to the blower motor 248, as will more fully appear from the following description of the wiring diagram; Fig. 11.

If' for any reason the mechanical refrigerating unit is ineffective to maintain the sub-zero temperature required in the food compartments of the cabinet, the attendant will be apprised of such condition by suitable indicators (hereinafter described), and may then obtain and insert above the tanks 238 blocks of dry ice, which may be inserted through a door 256 by which access is obtained directly to the interior of the housing 232. When dry ice is thus used as a refrigcrating medium, the tanks 238, being filled with a non-freezing liquid, will serve as reasonably good conductors to conduct heat from the air circulated through the circuitous passageways in the tanks, to the dry ice, for evaporating the latter.

Electrical circuits and controls breaker for controlling the operation of the compressor motor, the latter will be controlled by the usual thermostatically operated or pressure operated switches, by which the temperature in compartment in secthe evaporator 'is maintained at a predetermined low value. Since such controls for refrigerating units are conventional, they are not illustrated in the diagram Fig. 11. I

As previously indicated, the two switches H4 and the switch 228 are adapted to control the supply of current to the tray driving motor 54. As will be apparent from Fig. 11, these three switches are connected in parallel, and upon their closure are adapted to energize a relay which has a mercury switch 256 in series with the motor 54. Thus, when any one of the switches H4 or 228' is closed, the driving motor 54 is energized.

The lamp 48 is provided with a switch 268, so that it may be turned off during the period that the cabinet is not being used. The thermostat 254 is connected in series with the blower motor 240, the motor being shunted by the winding of a double acting relay 218.

When the blower motor is being supplied with current, andhence the winding of relay 218 energized, a switch 212 is closed to connect a lamp 214 across the current supply lines 268, whereas when the relay 218 is de-energized, switch 216 is closed to connect a signal lamp 218 across the supply lines 268. 'The lamps 214 and 218 are preferably located at the end of the cabinet where they may be readily observed by an attendant (as shown in Fig. 1), whereby the attendant may determine whether or not the air circulating blower 238 is in operation. The lamp 218 may be colored blue to indicate that the temperature of the air in the food compartment is below the temperature required, while the lamp 214 may be colored amber to indicate that the blower is in operation and that the temperature is at a safe operating value. In addition, a red colored lamp 288 may be provided and have its circuit closed by the thermostat 254 whenever the temperature within the food compartment of the cabinet rises above a-pre-determined value, sufliciently high to indicate that the system is not operating properly,

Operation In the normal use of the cabinet by retail food supply establishments, frozen foods and other foods required to be kept at a low temperature to preserve their qualities are placed in the trays 32, each tray of a group being packed with a difierent food product and corresponding signs applied to the faces of the indicators 44. Surplus food received by the retail establishment may be placed in the storage compartment 138.

In normal operation, the refrigerating unit 226 will be connected for continuous operation to maintain the evaporator coils 228 and the surrounding tanks 238 at the required low temperature, while the thermostat 254 will control the supply of current to blower motor 248 and thus control the circulation of air from the food compartment of the cabinet through the circuitous passageways in the tanks 238 until the air in this compartment reaches the required low temperature. The blower 238 is preferably of suflicient volumetric capacity to be capable of completely changing the air contained in the food compartneously opened, the air within the cabinet, being in constant circulation would nevertheless maintain the food products contained in the trays 32 at the required low temperature.

Whenever a customer desires to purchase food products. he will operate either the handle 98 or the handle 99 to cause' circuitous movement of a group of trays, until the tray containing the product which he desires to purchase is adjacent the door l6, which he will be able to determineeither by watching the indicator 44 or by observing the contents of the trays as they move past the door. When the desired tray is in an accessible position, the customer will release the handle 98 or 99, whereupon the movement of the trays will be arrested and the trays locked in arrested position by means of the engagement of the associatedrod H6 with its notched plate H8, Since the contents of the trays are readily visible through the multi-pane window 46, the customen has an opportunity to observe the foods before opening one of the doors l6. By utilizing a single tray for two or more different kinds of foods, it will be readily apparent that the cabinet may be utilized for the storage, display and dispensing of a large number of different kinds of food prod ucts.

Whenever the contents of any tray become depleted, it may readily be refilled by replacement from the storage cabinet I38 which, as previously described, may be elevated to render the contents thereof accessible, by operation of the handle I50.

The cabinet, as a whole, is thoroughly insulated, so that the mechanical refrigerating unit maybe of relatively small capacity, and operate intermittently. Furthermore, whenever it is desired to use dry ice as the refrigerating medium, the amount of dry'ice which may be packed in the housing 232 will be sufficient to maintain the air in the cabinet at the required low temperature for an extended period. In some instances, where dry ice is available at a reasonable cost, it

may be used as the refrigerant continuously instead of only during emergencies, and under such circumstances the mechanical refrigerating unit may, of course, be omitted.

While I have shown and described a preferred embodiment of vmy invention, it will be apparent to those skilled in the art that numerous variations and modifications thereof may be made without departing from the underlying principles thereof. I therefore desire by the following claim to include within the scope of my invention all such modifications and variations as will readily appear to those skilled in the art, by which substantially the results of my invention may be obtained by the utilization of substantially thesame or equivalent means.

I claim:

In a refrigerating and display apparatus comprising a cabinet .having heat insulating walls; a window formed at the top of said cabinet, said window being formed of a plurality of spaced transparent sheets so as to provide insulation against heat conduction therethrou'gh, doors on opposite sides of said window openable to obtain access to the contents of said chamber, the combination of a plurality of groups of trays, indivldually controlled means for each group of said trays for moving said trays of a group successively past said window and one of said doors.

LEONARD F. CLERC. 

